Inclined current hydraulic classifier



Oct. 28, 1947. c. c. 'CLIFFORD 2,429,925

INCLINED CURRENT HYDRAULIC CLASSIFIER Filed Deo. 15, 1945 5 Sheets-Sheet1 MQT E W WJ Oct. 28, 1947. yc. c. cLxFFoRD 2,429,925

n INCLINED CURRENT HYDRAULIC CLASSIFIER Filed Dec.V 13, 1945 5Sheets-Sheet 2 i 5 5 9 9 5. 5 0 r if 5 w m. d M m 0 wai. p WC l p @MOct. 28, 1947.r c. c. CLIFFRD 2,429,925

INGLINED CURRENT HYDRAULIC CLASSIFIER [wir/@Varney Oct. 28, 1947, c.c.c|1FFoRD .2,429,925

INCLINED CURRENT HYDRAULIC CLASSIFIER Filed Dec. 13, 1945 5Sheets-SheetV 4 v 17.9 JEZ v171 (H4/w55 C C2 /FFO/QD,

Oct. 28, 1947. c. c. CLIFFORD INLINED CURRENT HYDRAULIC CLASSIFIER FiledDec. 15, 1945 y 5 sheets-sheet 5 m GN mwN m.; NmNcc/H s n TL ww www mwN@T@ 0N Nm. Mm. RSN/ R555 U QQ, MMMQ.. QN@ @5525 @MJ hmwm/NQN um Z @um .NND; .5.6m o o c o o o o o o o o o o o o o o ohwhohhok @No um o F9@ o yN.0| o mm2 o w O o O O M O\ O O\\ mv o o o QN o M o o M o .o o o o o o o oo .I |.Il O o o Q o O O |O||||| o o o o o o o o M/UN/ o o .OQQA Mfmmwmmm E, o o o o o o o MOMQNM o M\N \M TW'MQN OMQNO o o o 0 o o o O o O 0Vo O O O 0 0 O O O OO O O 0 O O 0 O O O O l O O O O O Sm SISEI PatentedOct. 28, 1947 INCLINED CURRENT HYDRAULIC CLAS SIFIER Charles C.Clifford, Coleraine, Minn., assignor to Oliver Iron Mining Company, acorporatlonof Minnesota Application December 13, 1945, Serial No.634,691

8 Claims.

In the concentration of nely divided iron ores, such as low-grade,non-magnetic iron ores, by the so-called sink-and-iloat method, it iscustomary to separate the valuesi. e., the finely divided iron ores such.as hematite-from the associated tailings, to a classification in aliquid pulp medium, which is a suspension of a material in water that isso adjusted with reference to specific gravity as to allow the values tosink through the said heavy medium which retains floating the silica andother gangue materials that were originally associated with the ironore. This separation is due to the difference in specific gravities ofthe ore and the silica, slimes, and other waste materials groupedtogether generally as tailings; and in practice, the separation of theore and tailings is fairly clean, although a certain amount of ore isentrained in the tailings and the classifying heavy medium which, as hasbeen said before, is an aqueous suspension of high-grade hematite inwater, where low-grade hematite is. the material being classified. Thissuspension is proportioned so that the specific gravity thereof isfavorable to the gravity-settling therethrough of the ore values, andthe retenti-on of the waste tailings as a float on the heavy medium.

In another process, water itself may be used as the separating medium,the classification being effected by agitation of the water by air, theclassication being performed again by gravity due to differences inspecic gravity between the values and the tailings.

In either procedure, a certain amount of ore values is tied up in thetailings; also, where a heavy medium pulp comprising a water suspensionof hematite, galena, or the like, is employed as the classifying medium,the suspensoid of the pulp needs to be recovered from time to time, andregenerated.

The present invention, therefore, provides a second, or tailingsclassifier, which receives tailings, or heavy medium, or both, from themain classifying tank where, in the tailings classifier, a furtherseparation of values from the tailings is effected.

The improved construction of the tailings separator of the presentinvention is shown in the accompanying drawings, wherein:

Figure 1 represents a sectional elevation of the improved tailingsseparator of the present invention, the view beingr taken along thevertical center line of the tank.

Figure 2 is an end elevation of the apparatus of Figure 1, the viewbeing taken on the plane of the line II-II looking in the direction ofthe arrows.

Figure 3 is a longitudinal sectional velevation through one of the sprayboxes forming a part of the improved construction of the presentinvention, the View being taken on the section line III- III of Figurel, looking in the direction of the arrows.

Figure 4 is a view similar to Figure 3, looking in the oppositedirection, through a spray box similar to that shown in Figure 3, theview being taken on the line IV-IV of Figure 1, looking in the directionof the arrows.

Figure 5 is a detailed transverse sectional elevation showing furtherdetails of construction of the spray boxes of Figures 3 and 4, the viewbeing taken on the line V-V of Figure 4, looking in the direction of thearrows.

Figure 6 is also a transverse sectional elevation of the spray boxes ofFigures 3 and 4, the view being taken on the line VI--VI of Figure 3,looking in the direction of the arrows.

Figure '7 is a longitudinal sectional elevation of a second form ofspray box employed in the present improved construction, the view beingtaken on the line VII-VII of Figure 1, looking in the direction of thearrows.

Figure 8 is a detailed transverse sectional elevation of the spray boxof Figure 7, the view being taken on the line VITI- VIII of Figure 7,looking in the direction of the arrows.

Figure 9 is a further detailed sectional elevation of the spray box ofFigures 7 and 8, the view being taken along the line lX-IX of Figure 8,looking in the direction of the arrows.

Figure l0 is a detailed transverse sectional elevation through the sprayboX of Figures '7 and 8, the View being taken on the line X-X of Figure9, looking in the direction of the arrows.

Figure 11 is a sectional plan view showing details of a sidewall-structure of the tank of Figure 1, the view being taken on the lineXI-XI of Figure 1, looking in the direction of the arrows.

Figure 12 is an enlarged sectional elevation Y Showing the mounting of.the spray boxes in decritical,

end wall B extending the full height of the tank and a substantiallyvertical end wall C opposite to the end wall B, the wall C being a shortvertical lip at the top of the tank, a sloping end wall D joining thelip C and the bottom E of the tank. The sloping end wall D slopes to-thenarrow bottom E ofthe tank at an angle of approximately 45 'to vthevertical. This angle is not critical beyond being sufficiently sharp soas to enable a rapid settling of the heavy values and suflicientretention of the lighter .slimes .and tailings.

As will be seen from Figure 1, the tank is provided wth a number ofbafiies. 'Thetailings to be classified are received into the tank 1A.over the short `wall C, as indicated by the arrows. In Figure 1, thesolid arrows lpointingdownwardly indicate the values settling out,whether these be ore or heavy medium from the main separating tank, andthe broken arrows indicate the direction of flow of the tailings.

It will be seen fromthe view ofFgure 1 that there are two transverselyextending, substantially-spaced 'baffles i3, i5 Vextending across theltop of Athe tank A. VThe tank A is divided longitudinally into a seriesof compartments rby a plurality of sloping baille plates i1, i9, 2|, 23and 25, all of which compartments `communicate with downward end passage21 whichin'eiectis a downward .continuation of a space or compart-.-ment -29 at the Itop of the tank,this space `or compartment 2-9 beingdefined -by the 4angle of slope-of the baille'plate-|1..and the lengththereof. This chamber 29 is large .in volumetric content, .the Vpassage2l progressively narrowing .from the top-to the bottom lof the tank.owing .to the Vslope of 4the-end fwall D.

The baffle plate -|-1 'hasan upwardly sloping portion 3| which narrowsAthe cham-loer 29, Ias

shown, adjacent to `the tailings off-take -end of the Chamber, theremainder of the `baffle sloping downwardly at approximately right`angles .to the end wall D. This angle is not particularly although .itshould be substantially greater kthan the angle of `repose of thevalues,

.sothat :these values .wi-l1 fall readily from the .baille into thepassage 2-7, w-hich y:passageserves as a collecting passage ior `thevalues, .guiding them intoa .bottom .orcollecting compartment 33 ,forthese values.

The compartment 29 may -be termed the vprimary separationcompartmenasincein this compartment .the velocity .of ,the incomingtailings is dropped sufficiently .to allow .sedimentation .of the majorportion of the lheavy .values ,from the slimes and gangue, the velocitybeing reduced first b y impact of the incoming mixture .against .thetransverse -bailie plates i3, l5, and vsecondly by the 'large volume .ofthe compartment .2.9.

Some of the heavy values .settle immediately through passage 21 and passto the collecting compartment 33. Otherportions .of the initially.separated values fall on the baille plate il, slid ing therefrom intopassage '21.. 'In this .connection it may be noted that the apex '35ofthe Vangle. of bend of the baille plate il serves as an additionalbaille .for retarding the flow-of material thereover, causingadditionalvalues to settle out.

This action continues `:in the remaining compartments, .each bailleplate wIl), 2|, -23 and 25 having a similarly bent conguration as shown.Sections .|,9'., 2|, .23 and `25 are sloped up- Wardly from the junctureof the baffle plates at :therear wall B, and, then bent downwardly `toform a substantially disposed vertical baille, indicated at I9, 2|, 23and 25, the baiile then sloping downwardly to the passage 2l inspacedapart parallel relation, forming compartments 31, 39, 4| and 49Ibetween adjacent baille plates. These successive compartments arenecessary Vin order to eiect progressive separation between .the heavyvalues and lighter gangue that is entrained in the values descendingfrom the in- .itial separating compartment 29.

.In .order to eiect this further classification, the sloping end wall Dis provided, with a plurality of spray boxes indicated at 45, 41, 49, 5|'and 5.3 inFigur-e 1, which are positioned, respectively, oppositely tothe compartments 3l, 39, 4| and 543, and are adapted to direct jets or`.sprays of water, delivered thereto through supply pipes 55, 5l, 59, Siand 63 in communication with supply header 65, into these compartmentsacross the passage 2l, as will be eX- .plainedin `detail hereinafter,although the .resulting separating currents and effects thereofare1clear from Figure 1. The rdetailed-construc- `tion of `these sprayboxes will be pointed out hereinafter, but wit'will be seen that thesesprair .boxes .are of two types, those indicated atv45, 4l a-nd 49 beingsimilar butdifferent in'type Afrom ,spray boxes 5I `and53 which,however, are similar to each other, the -spray boxes 45,41 and-49 beingadapted .to deliver smaller jets of `water into the compartments 37|, 39.and 4|, Where less water is required to wash .the pulp passing.downwardly through passage 2l. The bottom vof the sloping end wall D isconstructed accordingly. From Figures 3, 4, 5 and 6 it willbeseen thatthe spray boxes 45, ll'l and.4i9 embrace .a control that is inthe natureof a sliding valve which controls `the ingress ofthe water'from thesespray boxes, whereas spray boxes v5| and '53 show a -blade arrangementVfor contro'llingthe larger volumes of water required for washing theore into compartments 4| and 43.

Figures 11 and'1'2v show the construction ofthe 4bottom of the slopingend wall and details of the mountings of the spray boxes thereon.

For receiving jets from the spray boxes 45, 4l Aand 49, the bottom ofthe sloping end wall D has a plurality of holes extending across thesurface VVof the end wall. AThese holes are indicated at El,

269 and 7|. Each spray box 45, 4l and 49 comprises a housing i3 which is-U-s'hap'ed in longi- `tudinal .cross section, the ends of the sides of'the U having oppositely extending attachment flanges 75, 'l5 which reston the Water-tight 'gasket 11,'the housing 'i3 being attached suitably`to the Vend wall Dby screws, rivets, orV bolts indicated at 79 which`pass through the water-tight gasket or packing Tl and tightly hold thehousing :13 against the packing TI for preventing leakage of uwatertherearound. Supply pipes for incoming water enter the housings 'l5laterally thereof, as shown Ain detail in Figure 12. Excess water leavesthese housings l 5 through outlets 8 i, which Yare-sufficiently large topermit cleaning out of any blade-valve suitably mounted in guide |0|"and which lifts out and in relative to the slots 99 by proper leverinstrumentalities, as shown in detail in Figures 7, 8, 9 and 10 of thedrawings.

In Figure 12, the right-hand blade I0| is shown as being in closingposition relative to its slot 99, whereas the left-hand blade |0|' isVshowin in retracted, or open position. Also, the inner surface of theend wall D is shown as being provided with a plurality of spacedtransverse ribs |03 which extend across the inner surface of the wall.These ribs |03 are in alignment with the baiile plates |1, I9, 2|, 23and 25, and serve to deflect the jets or sprays of water from the sprayboxes onto the baffle plates and into the compartments 31, 39, 4|, and43. lThe main function of these ribs,V however, is to form a dam orhurdle to check the flow of the heavier particles that are not insuspension but which lie on the sloping end wall D and which are slidingdownwardly thereon. These particles, if not guarded or checked in theirflow, might obstruct the spray openings to prevent proper operationthereof and of the control valves therefor. These ribs |03 also formreinforcing means for the end wall D at the point where the heavy valvesare attached to the end wall. It will be understood that the tankstructure is of thin plate steel and the control valves for the sprayopenings are heavy in construction. From Figure it will be seen that theslide bar controlling the spray -openings must t tightly and evenly incontact with the sloping end wall D in which the spray holes arelocated, in

terial settling through the tank and to wash the l said materials intothe classifying compartments, as explained above. The pressure behindsuch water is to be controlled in accordance with the density of thematerial being classified, higher pressures and velocities beingrequired for dense or heavy slurries of mud-like consistencies enteringthe tank than when the material has less density. The said pressures,however, must be sufficient to support the material flowing through thetank and prevent the saidmaterial from running out through the sprayopenings.

Details of operation of the spray box controls may now be referred to,reference being had particularly to Figures 3, 4, 5 and 6 for thedetails of construction of spray boxes 45, 41 and 49 shown in Figure l.As has been noted above, Figure 3 is a sectional elevation on the lineIII- III of Figure 1, looking at the end of the spray box housing, andshowing operating mechanism for opening and closing the intake holes 61in end wall D. Figure 4 is a section through the housing showing detailsof such mechanism inside the spray box housing.

Mounted on the end wall D is an extending bracket |05 which forms thefulcrum |06 for lever |01, as well as the mounting for this lever. Lever|01 has a handle portion |09 which is adapted to be grasped manually byan operator. -1 An actuating piston rod passes through the wall of thespray box housing through a bearing ||3 which includes a packing gland||5, as shown, for preventing leakage of water therearound. The pistonrod has a flattened end ||1 for receiving a bolt or equivalentattachment |9 that connects the rod to an actuating bracket |2| thatconnects with a sliding valve control member |23 having holes |25therethrough which register with holes 61 in the end wall D. It will benoted that the holes |25 are larger than the holes 61, in order toassure a free flow of water through holes 61.

The sliding valve member is, in practice, a sliding bar, the ends ofwhich are slidably mounted between the iianges 15 of the spray boxhousings 13, and the packing gasket 11 between the flange 15 and the endwall D of the tank, sufficient movement being permitted for the valvebar |23 to slide'until holes 61 become closed by the solid portions ofthe bar between and around the holes |25. The valve-actuating rod ispivoted to lever |01 by a pin |21 passing through yoke end |29 of therod and through a hole in the lever provided for this pin. It will beseen that this juncture between the valve-actuating rod I and lever |01is toward the iulcrum |06, but between the fulcrum and handle |09, lever|01 vacting in a manner similar to a brake lever. Bearing ||3 for therod is assembled with a cover which rests on annular sleeve |3I, cover|33 being held inr place by spacer bolts |35 held by nuts |31. Holes |25in valve bar |23 are substantially larger in diameter than the holes 61,thus assuring a supply of clean water to the holes 61 and thence intothe compartments between the baiiles.

Reference may now be had .to the construction of the spray boxes 5| and53, shown in Figures 1 andy 12, and in detail in Figures 7, 8, 9 and 10.

A s has been pointed out above, the housings 93 are bolted on thesloping end wall D through iianges 95 and screws, bolts or othersecuring means 96. Outer end flanges |39 on the housings 93 form seatsfor acover 4| that is bolted or attached in equivalent manner to eachange |39, byL fastening means |46. The cover |4| has holes therethroughfor the passage of lever arms |43, |45 that are joined at their innerends to the valve blades |0|, |0I through bolts or equivalent at- .and|45 have outer connecting yokes |63, |65

that receive an equalizer link |61 that is pivotally connected to thearms |43, |45 through bolts |69, |1|.

Fivotally connected to equalizer link |61 through bolt |13 is a floatinglink |15 to which iioating link is attached pivotally through bolt |19the end of a lever |8| that is fulcrurned at |83 to a standard |85 thatis suitably attached to the end wall D. By 1this arrangement the valveblades |0|, |0I are raised and lowered relative to the slots 99, therebycontrolling flow of water therethrough. The blades |0|`, |0| areprovided with a stop or abutment rib- |81 thereon which limitsmovement'of the blades into their respective slots. n y

As has been explained above herein, the feed v7 =enterstthe tank A whichis iilled with water, over the Vertical lip-C of theend wall where,owing "to vthe large vspace in the compartment 29 and lthe bailleplatesI3 and l5, the speed of flow is Vchecked and the ore or pulp immediatelystarts .to'settle out, while lightest portions of slimes and gangue arecarried up over angle 35 which permits passage thereof to the tailingsdischarge which will vbe referred to hereinafter.

`As the values flow from compartment 29 into passage -21, they are .metwith a streamof clean water Vfrom spray box 45. This stream or jet isunder considerable pressure, and forces values land entrained tailingsupwardly in compartment 31 and against vertical baffle i9, over whichlighter portions of slimes and tailings are driven to the dischargetherefor.

The-heavy values settle on top of baille I9, from which they are removedpartly by sliding there- .from-by gravityand partly washed off by thejet or tspray of water from'spray box 45, the heavy lyall-iesreturningto the settling passage 21 where they mee-t the jet orspray from sprayboX 41, the above `action being repeated in compartment 39, landt-hencein the successive compartments until the #thoroughly cleaned valuessettle into collect- .--ing compartment 33 for withdrawal through out-;let |81 in the bottom E of the tank.

.There now remains to be described the withdrawal of the slimes,'ganglia and other constituvrents of the tailings. In this connection,reference maybe had particularly to Figures 1 'and 2.

It has been pointed out above that the baflles |1, |19, 2|, V23 and 25arecomposed of an upwardly sloping section f3|, I9', 2|', 23 and 25',which sloping sectionfends in bailies defined by the angle -35of the topbaille I 1 and the vertical baille walls I9, 2|, 23 and 25". The slopeof the said sections is upwardly from the-end wall B of the tan-k -I-I,so that the intersection of these upwardly sloping sections-and the endwall-constitutes the lowest level in each separating compartmentin whichthe slimes, gangue and other tailings constituents separated in eachcompartment can-collect. At this lowest levellin each compartment opensthe withdrawal ducts indicated at |89, 119|, |93, |95, |91 and |99respectively, these vducts .passing alternately through lopposite sidewalls .20|, 203 of the tank A, these ducts acting as siphons in eachcompartment,-to withdraw the ,lighter .materials and tailings carriedinto the respective sections of 'the classifying compartments by theaction of the water jets or sprays. Except for the top tailings ductorpipe |89, the remainder of the tailings ducts are provided with :a4.butterfly valve in each, indicated respectively -at .205, 201, 209,2|| and 2|3. Proper lregulation vof those `butterfly valves will forcethe greatest 'part of the tailings ilow through the top pipe |89, theflow'through these pipes creating a circulation through the tank thatfacilitates the settling of the values or pulp and free passage `thereofinto the bottom collecting compartment `33, The bottom discharge pipe|99 is provided beneath Athe lowest level of the section 25 of the`bottom baille 25 for withdrawing any light or Ytailings constituentsthat have no-t been separated previouslyand which float on the ypulpcollected .in the settling compartment 33, the siphon action .of ythepipe |99 skimming off these floating constituents `from the top of thepulp collecting in 4thecompartment 33. The tailings and lightfma-.terials withdrawn from each compartment are collected in receiver 2|'5from which they lare Y.withdrawn vthro-ugh outlet 2 |1.

Since the vgreatest volume Vof slimes, tailings Vand vthe like iscarried over the apex of angle 35 in the compartment 29, the topoff-take pipe |89 is the largest in internal diameter of all of theseoiftake pipes. It will be understood that the tank A is illled withwater, and the currents set up by the jets or Sprays fromthe spray boxesare impeded by the substantially Vertical baille surfaces presented ineach of the classifying compartments, such baille surfaces (representedat 35, I9, 2|, 23" and 25") forming retaining walls which prevent anysubstantial amounts .of the heavy values from passing into the sumpsections of these classifying compartments, in which sump sections therespective offtake pipes open, only the lighter constituents such asslimes and tailings passing over these retaining walls into the saidsump sections. The Siphon action of the offtake pipes withdraws suchslimes and tailings from the sumps with the minimum of agitation,thereby avoiding any remixing of such constituents with the values.

There is effected a progressive cleaning of the values as they pass fromthe top to the bottom of the tank through the action of the laterallydirected series of jets or sprays of clean water that continuouslyengage the material at successive descending Vertical levels, washingthe material upwardly onto the succeeding baille plates where theprogressive cleaning occurs; whereas in all other known separators ofthis general'type the water jet at the bottom of the tanks must forceall of their tailings over the top. Another advantage of the presentimproved apparatus is that it is designed to take all 4of the tailingsfrom any preceding classifying equipment in the system without theinterposition of any thickening or dewatering instrumentalities; and theseparator of the present invention requires no power or pumps to operateit, the separation being accomplished entirely by gravity and cleanwater pressure.

I claim:

1. Apparatus for concentrating mineral materials, which comprises, incombination, a classifying tank having upwardly diverging side walls, avertical end wall, a sloping end wall oppositely disposed with respectto the vertical end wall, and a bottom, the said tank being adapted toreceive through Yits upper portions a iiow of liquid bearing thematerials to be classified, a plurality Vof horizontally spaced verticalbaflles adjacent to the liquid intake of the tank and adapted to check'the velocity of the incoming liquid, the said bailles extendingtransversely across the tank, a plurality of vertically spaced baffleplates eX- tending longitudinally of the tank between the side walls ofthe tank and from the Vertical end wall towards the sloping end wall,the said baille plates being positioned one above another and deningclassifying compartments between them, each of the said baille platescomprising a plurality of sections which define, respectively, a sumpsection adjacent to the vertical end wall and to the side walls, arestraining section for preventing passage of heavy material beingconcentrated to the sump section, and a sloping section which slopesdownwardly towards the sloping end wall but terminates short thereof fordeilning a settling passage through the tank, the slope of the slopingsection of each baille plate and the slope of the sloping end wall ofthe tank vbeing greater than the angle of repose of the heavy materialbeing concentrated, there being a collecting compartment for cleanedheavy material between the bottom baille plate and the bottom of thetank and a relatively large material receiving compartment in the upperportion of the tank above the top baifle plate and including the saidvertical transversely extending baffles, the settling passage having thematerial-receiving compartment, the classifying compartments and thecollecting compartment opening into it, means for washing materialsettling through the settling passing upwardly along the'said baifleplates in series and in the ,classifying compartments, whereby lighterconstituents of the materials and shines are caused toA pass over therestraining section of each baffle. plate which the heavy materialsreturn to the settling passage for progressive removal of lighterconstituents, and slimes therefrom in each succeedingelassifyingcompartment, the heavy materials viiowing countercurrently to admissionof washing liquid through each classifying compartment and beingsubjected to clean washing liquid as the heavy materials settle throughthe settling passage while lighter tailing constituents and slimescollectin the sump sections of the baile plates, means for siphoningcollected tailings and slimes from the said sump sections, and means forwithdrawing cleaned heavy materials from the collecting compartment.

2. Apparatus for concentrating mineral materials, which comprises, incombination, a classifying tank having vertical side walls, a verticalendrwall, Aa sloping end wall oppositely vdisposed with respect to thevertical end wall, and a bottom, the said tank being adapted to receivethrough the upper portions a ow ,of liquid bearing the materials to beclassified, the said tank being also vadapted to be filled withclassifying liquid, a plurality of spaced baille plates extendinglongitudinally of the tank between the side walls of the tank and fromthe vertical end wall towards the sloping end wall, the saidV bailleplates being positioned one above another, and defining classifyingcompartments betweenthem, eachVv of the said baille plates comprising aplurality of sections which denne, respectively, a sump section`adjacent to the verticalend wall and to the side walls, a restrainingsection for preventing passage of heavy material being concentrated tothe sump section, and a sloping section which slopes downwardly towards'the sloping endwall but terminates short thereof for delining asettling passage through the tank, theslopeof the sloping section ofcachi'baflle 'plate andthe slope of the sloping end wall of the tankbeing greater thanthe angle of repose` vof the heavy material beingconcentrated, orifices in the sloping end 'wall of the tank forinjecting classifying liquid into thetank, the orices being disposedsubstantially in alignment with the baiile plates vfor forcing materialto be classified from the settling passage lupwardly vof the bailleplates, jets of liquid from the said orifices carrying lighter tailingsand slimes upwardly of the baie plates over the restraining sectionthereof for retention in the sump sectionl'while heavier values passdownwardly of the baille plates countercurrently of the said jets, andmeans for supplying fluid tothe said orices under pressure for formingthe said jets, the orifices extending transversely across thev slopingend wall of the tank. Y

' 3. AApparatus for concentrating mineral materials, which comprises,inv combination, aclassifyingtank having Vertical side walls, a verticalend,wall,a sloping end .wall oppositely Vdisposed with respect tothevertical end. wall, and al bottom, the said tank being adapted toreceive through the upper portions a ilow of liquid bearing thematerials to be classified, the said tank being also adapted to be lledwith classifying liquid, a plurality of spaced baffle plates extendinglongitudinally of the tank between the side walls of the tank and fromthe vertical end wall towards the sloping end wall, the said bailleplates being positioned one above another and defining classifyingcompartments between them, each of the said baffle plates comprising aplurality of sections which define, respectively, a sump sectionadjacent to the vertical end wall and to the side walls, a restrainingsection for preventing passage of heavy material being concentrated tothe sump section, and a sloping section which slopes downwardly'towardsthe sloping end wall but terminatesshori; thereof for defining asettling passage through the tank, the slope of the sloping section ofeach baffle plate and the slope of the sloping end wall of the tankbeing greater than the angle of repose of the heavy material beingconcentrated, orices in the sloping end wall of the ytank for injectingclassifying liquid into the tank, the orices being disposedsubstantiallyin alignment with thefbaiile plates for forcing material tobe classified from the settling passage upwardly of the baiiie plates,jets of liquid from the said orifices carrying lighter tailings andslimes upwardly of the baflle plates over the restraining sectionthereof for retention in the sump section while heavier Vvalues passdownwardly of the balile plates countercurrently to the said jets, meansfor controlling the said orifices and instrumentalities for supplyingfluid under pressure to the said orices for forming the said jets, thesaid orifices extending across the sloping end Wallsl of the tank.

4. Apparatus for concentrating mineral materials, which comprises, incombination, a classifying tank having vertical side wa1ls,'a verticalend wall, a sloping end wall oppositely disposed with respect to thevertical end wall, and a bottom, the said tank being adapted to receivethrough the upper portion a flow of liquid bearing the materials to beclassified, the said tank being also adapted to be filled withclassifying liquid, a plurality of vertically spaced bale platesdefining classifying compartments between the baffle plates, a pluralityof series of transverselyextending uid intakes extending across thesloping end wall in substantial alignment with the baffles, means forinjecting liquid through the intakes for washing material settlingthrough the tankonto the bales in succession, thereby progressivelyfreeing the settling materials from slimes and light tailings Whilepermitting cleaned heavier values to settle to the bottom of the tank, aspray box for supplying liquid under pressure to each series' ofintakes, and means for controlling flow of liquid through the apertures.

5. Apparatus for concentrating mineral materials, which comprises, incombination, a classifying tank having side walls, a vertical end wall,a sloping end wall oppositely disposed with respect Vto the vertical endwall, and a bottom, the said tank being adapted to receive through theupper portion a flow of liquid bearing the material to be classified,the said tank being adapted to be iilled with classifying liquid, aplurality of vertically spaced baiie plates defining classifyingcompartments between them, liquid injection means extending across thesloping end wall and being disposed to inject classifying liquid intomaterial settling through the tank for washing the saidmaterial intoeach succeeding classifying compartment as the material settles throughthe tank, thereby progressivelyV cleaning the materialA of slimes andlighter tailing constituents, means for supplying liquid under pressureto the liquidinjection means, and mechanism for controlling the amountof liquid passing through the liquid injection means.

6. Apparatus for concentrating mineral materials, which comprises, incombination, a, classifying tank having side walls and end walls, and abottom, one of the endwalls sloping inwardly to the bottom, the saidAtank being adapted to receive through its upper portion a flow of liquidbearing the material to be classified, the said tank being adapted to belled with classifying liquid, a plurality of vertically spaced bailleplates defining classifying compartments between the baille plates, aplurality of vertically spaced liquid intake orices extendingtransversely across the sloping end wall of the tank, the orificesbeing' disposed to project jets of liquid into the said classifyingcompartments and across a stream of material settling through the tank,whereby the said materialV becomes washed upwardly into each succeedingcompartment for successive separation of slimes and light tailingconstituents therefrom, certain of the said orifices being series ofspaced holes through the sloping end wall, others being slots in the endwall, spray boxes mounted over the orices for introducing liquid underpressure through the orifices, control means for the orifices, thecontrol means for each series of spaced holes comprising a horizontallymovable drawbar having holes therein of a diameter larger than thediameter of the holes in the sloping end wall but corresponding innumber and spacing to the holes in the end wall, the control means foreach slot comprising a vertically movable blade adapted to t into theslot for closing the same, means for actuating the drawbars for movingthe holes therein into and out of registry with the holes in the slopingend wall, and mechanism for operating the blades, the said mechanismincluding equalizing linkages for the blades and a lever for applyingpower to the equalizing linkages.

7. Apparatus for concentrating mineral materials, which comprises, incombination, a classifying tank having side and end walls` and a bottom,one of the end Walls sloping inwardly to the bottom, the said tank beingadapted to receive through its upper portion a lloW of liquid bearingthe materials to be classified, a plurality of vertically spaced bailleplates in the tank extending towards the sloping end Wall but stoppingshort thereof to provide a material settling passage, the said bailleplates defining classifying compartments between them, each of the saidbaille plates comprising a plurality of sections which define,respectively, an inner sump section adjacent to the side Walls and to anend wall opposite to the sloping end wall, an intermediate restrainingsection for preventing passage of heavy material being concentrated tothe sump section, and a sloping section which slopes downwardly to thesettling passage, the slope of the sloping section of each baille plateand the slope of the sloping end wallV of the tank being greater thanthe angle or repose of the heavy material being concentrated whileimpeding settling of the heavy material, there being a collectingcompartment for cleaned heavy material between the bottom baille plateand the bottom of the tank and a relativelyl large material receivingcompartment in: the upper portion ofthe tank above'. the topy bailleplate, the sal'cl settling passage having the material receivingcompartment, the classifying compartmentszand the collecting compartmentcommunicating therewith, ar plurality of liquid intake orices extendingtransversely of the sloping end wall, the. saidv orifices being spacedlengthwise ofthe slopingA end wayl in rows one above another, the saidorifices. being disposed to project jets of classifying liquid acrossthe settling passagefor Washing material settling through the settling.passage into theV said classifying compartments whereby the said.material becomes washedineachi succeeding classifying compartment forsuccessive separation of slimes and light tailing constituentstherefrom, certain of the said orifices being rows; of spacedV holesextending through theslOping endl wall, others being slots in the saidsloping end wall, spray boxes mounted"v over the orifice for introducingliquid under pressure through thev orifices, control means for theorifices positioned in the spray boxes, the control means for eachseries of spaced holes comprising a horizontally movable drawbar havingaligned holes therein Aofa diameter larger than the' diameter ,of theholes in the sloping endl wall but corresponding in number and spacingto the series of holes in the endV wall', the control means forleachslot com prising a vertically movable blade adapted' to fit into theslot for closing the same, lever means for actuating the drawbars formoving the holes therein into and outvv of registryV with the holes inthe sloping end wall, mechanism for operating theblades, the said'mechanism including equalizing linkages for the blades and alever forapplying power to theequal'izing linkages, siphon means for removingslimesv and lighter tailings from the sumpsections oftliebaiilev plates,and meansfor withdrawing cleaned concentrate through the bottom of thetank.

8. Apparatus for concentrating mineral materials, which` comprises', incombination, arclassifying tank having' side and? end walls, a pluralityof spaced' baille-plates, vertical; side walls, a vertical end wall, andav sloping endY wall oppositely disposed with respect tothe verticalendwall, and a bottom, the said* tank being adapted to receive through itstop a llowA of liquid bea-ring the materials to be classified, the'sloping endl wall receiving primaryv settling of heavy materials to beclassied; then saidl slope beingof Yan inclination effective forsubstantial retardationof movement of materials passing jtherealongtothe bottom ofthe tank but greater than the angleV of slope of suchmaterials, a plurality ofispacedv baille plates subdividing the tankinteri'orly into` a plurality of classifying compartments, the saidbaffle plates terminating short of the' sloping, end wall of the' tankforA defining a settling passage therethrough between the" bailleplates. and' the sloping end Wall, a plurality of aligned spray oricesfor introducing jets. ofk water through the. sloping end wall of thetank into thev materialY settling through the settling passage. andalong the sloping end wall, means for injecting theverselythereof. onits inner side, the said ribs:V

being positioned` adjacent't to but` in; advance of the; sprayv orificeswith. respect. tof moven'fientl off the material along the sloping endWall and through the settling passage, the said ribs form- REFERENCESCITED ing dams for material moving along the sloping The followingreferences are of record 1n the end Wall for preventing access thereofto the spray le 0f this Patenti orices with attendant stoppage of theoriices, 5 UNITED STATES PATENTS spray boxes under the spray orliicesmounted 0n the outside of the sloping end wall, means in Number N ameDate the spray boxes for controlling passage of Water 485,952 MelmckeN0V- 3 1892 through the spray orifices, and operating mech- 1,410,233Fahey Ma'- 21 1922 anism positioned exterioriy of the spray boxes for 10FREIGN` PATENTS operating the said control means. Number Country DateCHARLES CI CLIFFORD 312,047 Germany Maly 12, 1919

